The present invention is directed to a cathode structure and methods of manufacture, and more particularly to a cathode structure including a getter material and a diamond film and methods of manufacture thereof.
In the electronic arts, cathodes are required for many diverse applications. A cathode is an electrode by which electrons enter a system, such as an electrolytic cell or electron tube. Cathodes are also employed in X-ray devices, flat panel-display systems, microwave sources, radar, communications, high power fast switches, electron beam processing of materials, high gradient accelerators, and many other applications.
Cathodes are generally divided into four types: thermionic cathodes, laser driven photo-cathodes, field emission cathodes, and exploding or plasma field emission cathodes. Field emission cathodes may for example be used in vacuum applications.
Vacuum field emission cathodes produce an electron beam by Fowler-Nordheim quantum tunneling of electrons from near the Fermi level into the vacuum. A relatively large electric field is required compared to other cathode types. The large electrical field that is required can be obtained from enhancements of the applied field due to surface irregularities.
One example of a device that may employ a field emission cathode is a miniature X-ray device. One such X-ray device is discussed in the U.S. Patent application, Device for Delivering Localized X-ray Radiation to an Interior of a Body and Method for Manufacture, filed Feb. 21, 1997, U.S. Ser. No. 08/806,244, currently pending, which is incorporated herein by reference in its entirety. The X-ray device described in U.S. Ser. No. 08/806,244 is designed for use inside a body, and the cathode operates inside a vacuum chamber.
Flat panel displays also require small, effective cathodes in a vacuum environment, and field emission cathodes may be used for flat panel displays. It will be appreciated that there is a need for an effective vacuum field emission cathode that can be used in applications that are sensitive to space restraints.
Generally, the present invention provides a cathode structure, and a method for fabricating such a device. The cathode structure may be used for electron emission and includes a body comprising a getter material, and a diamond film on the body.
An embodiment of a cathode structure in accordance with the invention may include a substantially rounded portion and a substantially straight portion.
A method of manufacturing a cathode structure includes forming a body using a getter material, and forming a diamond film over the body.
An embodiment of a method in accordance with the invention may further include forming the body with a substantially rounded shape and conditioning the cathode structure.